I'm having trouble completing 100 cards/day in the FREE version of Lingvist

My free trial just ended today, so when I completed my 20 new words, Lingvist prompted me to do my daily challenge. I did that and then returned to the Learn section and did a few more cards because I hadn't reached 100 yet, but then after a few cards it told me I had reached my free daily limit.

Am I not supposed to be able to do 100 cards per day in the free version? I understand that I'm only entitled to 20 new words, but why is it stopping me from reviewing old cards? I'm just confused as to what I'm allowed to do as a free user.

Also, if I close the website for a few minutes and then come back to it, it lets me do a couple more cards before it once again tells me I've reached my limit. Am I supposed to leave it for a few hours to "recharge" before completing my 100 cards?

Ah yes, I think you're exactly right, Alex. I should have read the message more closely:

Lingvist Free daily limit reached
You have reached your new word limit for the day and practiced all your words. Come back later when our algorithm has generated more words for you to practice.
Alternatively, you can upgrade to Lingvist Unlimited and access more new words, along with a whole host of other great benefits.

[Emphasis mine]

I was just confused because I knew there were cards that I had answered incorrectly, and I didn't realize that the algorithm will only let you practice them again after a set amount of time.

I'm not staff, but given what you've described, I suspect that what may be going on is that Lingvist's algorithm is calculating that it's time to give you more new words, and because you've reached this limit already, it stops you.

When you take time away, and come back, there are more words that its algorithm calculates as you needing to practice, so it gives you these first. This way, you get a few new words, but again, you quickly reach the limit.

Lingvist could obviously fix this by making the algorithm either automatically put more words on your repeat stack, or by giving you the option to do so (telling you that it's time for you to learn new words, but this is limited, and allowing you to opt to repeat other words to get to the 100 limit.)

That said, I highly recommend the paid version. I've been using it for a year and it's really been worthwhile. I also like the idea of supporting Lingvist, because I think they've created an outstanding learning tool and I really want to see them compensated financially for the work that they're doing. If you pay by the year, the monthly rate is quite cheap. It's a great deal if, long-term, you plan on learning more than one language they offer.